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1988 80 HP Mercury carburator cleaning question

S

squire1

New member
My boat has been sitting indoors for about 6 years. I didn't have it winterized etc after last use so I figure the carburators are gummed up. So I have removed all three carbs and soaking them in Berrys carb cleaner and then blowing out with compressed air. Is this all there is to properly cleaning them? I blew out all the small passage ways etc. So far this has seemed pretty simple so I just wanted to see if this should be adequate to keep the boat from bogging down ( assuming no other problems ). I tried to clean them in past but only with carb cleaner ( no soaking and no compressed air ). The boat bogged down once I got past idle speed so I ended up taking it to the mechanic.
I am hoping to avoid that this time due to both time and money.

Also I am replacing the gaskets but floats, needle valve, jets all seem to be okay.

Thanks for any advice.
 
That's how I do it as well. Bogging can be cured by finding best idle then adding a 1/4 to a 1/2 turn OUT on the idle mixture screws.

Jeff
 
fastjeff said:
That's how I do it as well. Bogging can be cured by finding best idle then adding a 1/4 to a 1/2 turn OUT on the idle mixture screws.

Jeff
Click to expand...


So the idle screws actually control how the boat operates when I give it more throttle? That has always been when the boat wouldn't operate right. Perhaps I did clean carbs adequately in the past but had the idle screws set wrong. If I back screw out too far what will that do?

Thanks again!
 
Correct -----When they idle really nice they bog when accelerating.-----No accelerator pump.----Therefor they need to be a bit rich at idle.------No you won't go out too far.-----Try it and repost back.
 
Saw a great video on cleaning carbs at https://www.youtube.com/watch?v=8rgZwnH51aE using Berryman carb cleaner.

Will have to do mine ('92 Merc 40 4 cylinder 2 stroke) as soon as I can get the boat towed to a haul out. In the video, Berryman B12 is used.

Having a gasket kit is a good idea. One last thing on 2 strokes - I plan on doing the initial filling of the carb bowls with a mixture of 50:1 gas:eek:il to make sure oil gets to the engine at first start time.

I am guessing that if there are plastic parts in the carb ie. the floats in mine, they should be protected from the carb cleaner - removed if possible. Also, protect rubber stuff.

I guess that compressed air is used after applying carb cleaner to blow any loosened debris out.
 
Last edited:
racerone said:
Correct -----When they idle really nice they bog when accelerating.-----No accelerator pump.----Therefor they need to be a bit rich at idle.------No you won't go out too far.-----Try it and repost back.
Click to expand...

Okay Jeff I finally got my boat in the water and it ran great for my test
run. No bogging down with mid or full throttle. But then I took it to Lake Erie and it ran great with one problem. It would stall when I moved it from neutral to in gear to troll. I kept having to give it a bit more throttle to prevent a stall. No issues starting in a.m. cold or otherwise.
I was thinking perhaps it needs to be richer still but have read you have to adjust idle with boat in the water and in gear. Is this correct? Can I get it anywhere close on land with muffs. I gotta get it right as it is a bit unsettling stalling 5 miles from shore in Erie!

Thanks!
 
Jeff is the final word; some years ago, I was also adjusting the idle mixture screws on my '92 40hp 4 cyl 2 stroke Merc; 2 carbs; it too would stall when put in gear; I finally tied it to my dock, and adjusted the idle mixture screws while it was in gear with the prop under load; I went rich with the adjustment screws until it would not stall when putting it in gear; took a bit of doing with a few restarts; now I do adjustments while in my driveway, I put the lower unit in a Rubbermaid garbage barrel full of water and in gear with the prop turning to introduce load.
 
You need her to be fully warmed up and in gear--kinda like romance!

I add that bit of extra richness (1/4 turn out) as needed to prevent bogging. If there carbs had accelerator pumps on them this nonsense could be avoided, but...

Jeff
 
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